Anti-aircraft gunfire control



J. L. ROUTIN.

ANTI-AIRCRAFT GUNFIRE CONTROL. APPucATloN F1LED'1ULY 24, 1917.

, Patented July 6, 1920.

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l MILL j. L. ROUTIN.

ANTI-AIRCRAFT GUNFIRE CONTROL.

APPLICATION FILED IULY 24, 1917.

Patented July 6, 1920.

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ill nl www JOSEPH LOUIS ROUTIN, 0F PARIS, FRANCE.

ANTI-AIRCRAFT GUNFIRE CONTROL.

Specification of Letters Patent.

Patented July 6, 1920.

Application led July 24, 1917. Serial No. 182,597.

To all whom. t may concern.'

Be it known that I, JOSEPH LOUIS ROUTIN, a citizen of the French Republic, residing. at 2 Rue Olschanski, Paris, France, have 1nvented a new and useful Anti-Aircraft Gunlire Control, which is fully set forth in the following specification.

The present invention relates to improvements in tachy-chronometrical apparatus such as described in my application for patent Serial No. 182,311, tiled July 23, 1917, now Patent No. 1,345,697, dated July 6, 1920, and has for its object to provide a particular form of apparatus of the above kind which permits of' the direct determination of the product of either the azlmuthal or zenlthal velocity of an aerial target by the time of flight of the projectile without making any calculations.

In regulating the firing of anti-aircraft guns, it is necessary to apply a correction to the vertical and lateral directions of aim in order to compensate for the change of position of the aerial target during the time of flight of the projectile. This correction requires the determining of the angular zenithal and azimuthal velocities of the target and a knowledge of the time of flight of the projectile for an extrapolated or estimated distance of the target. Representing the Zenithal angle by oc, (a the azimuthal angle, and t2 the time of flight of the projectile as in the above application, then the zenithal and azimuthal velocities will be da do sought will be the products t2 and respectively, and the corrections da izda) c di and d# In the following it will be assumed, for instance, that one has to determine the product of the azimuthal speed by the time of transit which will be designated resp;-

tively as in the principal patent by and t2.

The principle employed consists in measuring directly the angular displacement of the target during the time 2, that is to say in the case under consideration, the horizontal projection of the angle e at which the target is displaced during the time t2.

ln practice it will be advisable to measure this displacement during a time 62-, the consant lvl being a greater number1 than unity and to amplify the measure in such manner as to facilitate the readings.

The accompanying drawings show one constructional form of the apparatus for accomplishing these-objects, in which Figure 1 is an elevation and Fig. 2 a plan view of the improved tachychronometer.

Fig. 3 is a detail view. Fig. 4 is a diagrammatic view illustrating the control of the electric circuits.

u Fig. 5 is a detail View showing the driving connections between a sighting device and the tachometer.

1. Fig. l is a drum actuated by the movement of the telescope L which may be mounted to turn either in a vertical or horizontal plane. For convenience of illustration, the telescope is shown in Fig. 5 as mounted on a vertical sector A meshing with a worm B- on a shaft C operated by a handle M. The displacement of the telescope is transmitted through multiplying gears D and gear shaft E to drum 1 which consequently turns at a speed proportional t E w o d, or d, 1n case the telescope were mounted for azimuthal angular variation.

2 is a second drum identical with the first and set in motion by it by means of a steel laterally toothed belt 3. The traction may be produced, for instance, by making perforations in the belt in which spurs 4 forming projections on the drum engage.

5 and 6 are two metal rods alon which can slide the sliding member 7, a lig t member shown separately in perspective in Fig. 3. These two rods are connected at the top and bottom by the two bell cranks 8 and 9 which can turn on the vertical shaft 10 and which carry the soft iron armature 11 which closes the magnetic circuit of the electromagnet 12.

It will be assumed, first of all, that the direction of rotation of the drum 1 is that indicated by the arrow. So long as the electromagnet l2 is not excited the spring 13 keeps the sliding member 7 away from 3 and the sliding member is drawn along at the speed 71:2 l-2 It is very evident that if the current is maintained during a time t2 (and it will be seen further on how this result is obtained) the distance traversed by the sliding member will be t2 (Cil-ct", that is to say, it will be proportional to the result to be determined.

In order to have a permanent indication a second sliding member 14 is arranged above 7, which slides along the fixed rods 15 and 16 and is normally in contact with the teeth of the rack 17 arranged so as to oppose the descending movement of 14. Each time that the electro-magnet 19 is excited this rack 17 fixed to a frame pivoted at 18 is separated from the member 14 which is then free to descend again until it meets the member 7. This effect is automatically produced during a very short period and shortly before the end of the rising movement of the member 7.

When the direction of rotation of drum 1 alters the current it does not pass into the electro-magnet 12 but into the third electro-magnet 21 which presses the sliding member 22 against the toothed steel belt 3. The sliding member 14 is then no longer raised by member 7 but by member 22. On each side of the belt 3 the teeth are so inclined as to insurethe traction of the sliding members 7 and 22.

It is the sliding member 14 which carries the index fingers 23 and 24 which move in front of the scales 25 and 26 respectively corresponding to each of the directions of rotation. Each scale is preferably divided in mils as adopted in gunnery, each mil being H10-6 of the circumference. In order equal to equal to to take into account corrections which do not depend on the speed of the target it is sufiicient to displace the two scales 25 and 26 in opposite directions by rotating the button 27 on the shaft of which is a gear 32 engaging racks 33, 34 on scales 25 and 26.

A sector 28 frictionally mounted on the drum 1 is drawn to the right or left according to the direction of rotation and displaces a bar 29 which covers one of the scales and only leaves visible that on which the readings are to be made. The abutments 30 and 31 which limit the course of this sector are used to form a switch to transmit the current as will be hereinafter described, through the post of telechronograph either to the electro-magnet 12, or the electro-magnet 21. This part of the apparatus is not illustrated in Fig. 2.

Fig. 4 shows how the current is automatically passed at the desired moment and during the proper time through the electromagnets. j

1a is a drum driven at a constant speed by constant speed means such as a clock or constant speed electric motor.

The periphery of this drum is provided in part with a conducting surface represented by the shaded portion of the drawing and limited on the one hand by the straight line 2--3 and on the other hand by the curve a b c. On this conducting surface, which is raised, rubs a brush 4a mounted on a nut e working on a threaded rod g connected through a flexible shaft to a hand-wheel V at the chronometrical station. The nut e is moved in such manner that its distance from the left extremity of the drum 1a is always proportional to the predicted distance D of the aerial target. The curve a 'b c is so determined that for each value of D the duration of the contact may be in proportion to the corresponding time of flight 252.

The current furnished by the battery 5a is sent to the tachychronometer either through the electro-magnet 12, or the electro-magnet 21 (see Figs. 1 and 2) according to the position of the switch 28 which is controlled as has been above stated.

The direction of rotation of the drum 1a is such that the rupture of the contact 4Zl is made on the rectilinear generator 2 3. A xed brush 6a which at every rotation comes into contact with a suitably placed tappet enables the electromagnet 19 to be excited during a short instant a little before the current is broken in the circuit fed by the brush 4a.

It is advisable to rotate the drum 1Cl at such speed that the time taken to perform one revolution is exactly equal to the dead time T which includes two distinct intervals separated by the moment of the discharge of the shot, namely (a) the time t, required for reading D0 and 10 to determine the height according to the scale, fix the elevation, correct the adjustment of the telescope in relation to the axis of the gun, regulate the fuse and load the gun.

(b) the time t2 taken by the projectile to reach its objective above it is also desirable to regulate the adjustment of this drum so that the contact of 4a ceases at the same moment that the firing officer has to make a new reading, that is to say, after each discharge of the gun. Then in spite of the discontinuity of the working of the apparatus there will be always strictly exact indications for the actual moment that they are needed.

The device as thus far described operates as follows: The drum 1 is assumed to turn with the movement of the telescope, which in the present instance follows the azimuthal displacement of the target. Sector 28 which performs the function of a switch and is held frictionally against the face of the drum is arrested by Contact pin 30 or 31, Figs. 1 and 4, depending on the direction of rotation of the drum. When the predicted distance D to the target is announced and the brush 4a breaks contact on the line 2 3, the brush is moved to a position along the timing cylinder corresponding to distance D. When the rotation of the timing cylinder brings the edge ab of the conducting surface under the brush 4a, a circuit is closed through battery 5a and the coil of magnet 12 thereby causing armature 8 of the latter to move sliding member 7 into engagement with traveling serrated belt 3. Sliding member 7 now moves at a speed log?- A short time before brush 4a breaks contact on the line 2 3, brush 6 momentarily closes a circuit through magnet coil 19 which attracts its armature rack 17 and releases a sliding member 14 provided with index lingers 23-24 This member drops onto slide 7 as it moves upward and just before brush 4a breaks circuit to stop the advance of slide 7. The distance traversed by the slide 7 during the time cor- 1 responding to a predicted distance D, is registered on the scale 25 by finger 24 for eX- ample. This reading is proportional to the azimuthal displacement of the target during the time of flight and affords the predicted correction 152%) for use at the next use in regulating the firing of anti-aircraft guns, the combination of a traveling member adapted to move at a speed proportional to the angular speed of the target, a scale for indicating the product of the time of flight of the projectile by the angular speed of the target, indicating means movable along said scale, means for engaging said indicating means with said traveling member, and timing means controlling the duration of said engagement in accordance with the time of flight of said projectile.

2. In chronotelemetrical apparatus for use in regulating the firing of anti-aircraft guns, the combination of an endless belt adapted to be driven at a speed proportional to the angular speed of the aerial target, a scale for indicating the product of said speed by the time of flight of the projectile, indicating means movable along said scale consisting of a slidable element having a separable registering index member, electromagnetic means for throwing said indicating means into engagement with said belt, and timing means including circuit connections with said electromagnetic means for controlling the duration of said engagement in accordance with the time of flight of the projectile.

3. In apparatus of the character defined in claim 2, the combination with said index member of a releasable support therefor, other electromagnetic means for moving said support, and an electric circuit including a timing contact for energizing said magnetic releasing means.

- 4. In chronometrical apparatus for use in regulating the firing of anti-aircraft guns, the combination of a drum adapted to be rotated by the angular movements `of a sighting telescope, an endless belt driven by saiddrum, two graduated scales arranged parallel and past which said belt travels, a sector frictionally mounted on said drum, abutments in the path of said sector, and a cover pivoted on the sector adapted to obscure one or the other of said scales depending on the direction of rotation of said drum, and a slide provided with time-controlled means for engaging the same with said belt.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

JOSEPH LOUIS ROUTIN.

Witnesses:

HENRI MoNIN, CHAs. P. PREssLY. 

